Electrooptical system



July 18, 1933.

J. J. ROGAN 1,918,827

ELECTROOPTICAL SYSTEM Filed Nov. 22, 1929 Patnte dfJulylls,

I I E SEIIS w w This inyeiitieh i'elates to .eleotro -optical systems and "in particular to. systems for t ansmitting Visual i epresentatins has for its main object the provisionfif methods and'niean's forsimplifyingwthetrans} mission lof pictures images or the -like.

Another" bjectef the invention to pro vide system -0 f television or 7 picture transmissidn'wherfeingfeater brillianey niay be at tained in the reproduced; image pr 'p letureif r -A featui'e, of-the invention;pertains-tea ables theimages or apictui'estoibe repreelueed and viewed hy an audience ilsing, agsingle V soilree bflightof highbrilliangy and uniifiifn intensityFAs a result of this featuregtheder feet which has been encountered in all;

systems "of television: heretofe're propfo'sed,

s 1 namely, the use bf lew"intensityfrep 'oducing lamps such {as Neon lanl 'psl or the like,

' avoided:

plicated opti al systeinss 7 1A still further.

large audience withput the neeessity o'f preovicling expensivelamp-bank's andthe necesmy 'commiitatingimechanism therefor; j '1 1 Other features and j advantages Qf' the in vention Will-b6 'e'vealegijup'on a considei'atien pended claims;

- be." disclosed" in cennection" with hnegwellknown type of transmission sys tem,f 1ijt": will he. understded that this is dbne merely for "the purpses 'pf description.

- While the br'oacl'id'e'a' of theinvention'vi ill he fdisclosed 'cbnne ctidn tx'rith the type Of s stem diselesed into-pending apglic'ationy erial *No. 409,002," referred to heieinabove,"

applied to 0 featt e ofr theini entien; to provide a television g 'eprodu c'ingssystem is wherein the reproductionmaybe viewed ,a

of the fbllowing descriptions and" the I ap .cur'l entsflnay be further amplified indieatedsChematiCalIy by the" block 9. Injthe JO N; 150G431, en humanism,:LeNGvistAm); QEWLYYOBK, iessieixtb tKTbPiiYGRADEQi-f 5 sYLvANIA coRPoRte'r1o1 or sALnM, vmssncnusmms ecqmqRATIoN-w AssA y'stems "Within; the 1 seepe thereof;

drawing shi Ws theinviention 'SY tBm-K I v a Fig. 2 is adetail-view'of One ofthe'elements itf'willfb'eunderstood that this-isimerelyffor v the 'pnrpses efsillustifatin gichem-defied mode; of carfyingioutfthe"invention, pThe 0 application 'ofth'e inventien to Other types-: v

dfthe nbvel sereenacwrding to the-invention;

.ffFig 3 shows mdamea formofscreen'em- I I j bod ing feat res,oftheinventi gy Figs-4 shows the invention a pplieclftoi ah othertypepftelevision?system;f- '7 V Referri pie particularly w Fig. J 1 the suitfable optical system, representedlschemati- T ,'ca11y hjfthe"nu nerallfinpon the filinl. ,f The 1 1 i'sucpessive' elemental areas; ofthei film l-are s a ne by y well k bw m s, Q' -V mple-s e show-11in Fig; 1'; a m ng spii'ally r 0 0 V I v fpeffqr'ated dise is positioned betweenthe thehovel ine'ansfer, simultaneously"pr'ddiicg film l ingthewisualjsensatiqnsof spatial and 'in tensitysva-riations Qwithout the 1 need of (join W lF FQQ rfih ip i p se dfill vtrationmerely, the representation'which is to b t an this-lr p e entab e m y:

light hi'c'htpassesthroqgheach suc ees'siVe' .pei'fpnatipnis projected t po'n the-lcelliby flmeanlsiof a suitable opticalsysteihfi, fThas I 'the-"e'e'll "5,gene1atescurrents aryiijn' acorclan cefwith the Varying transparencies of thesi ec'essiveelemental areasdf, the film f lt; These Varying jc'urrentsii may then lOe' iampli-i v hey fi st be m dula ed w h. a sbn o cai-rieneu I entfS will befclear to tho'se I At the receiving statieh, shown injthe s5, fled; t0. 'the ;freq1iired; level as indicated schematicallythetblpck? and eithel applied flire'ctly tbthe transmission ehannel L I 0 901,; I v i familia'rjwith the carrier ti'anslnission art;- I W l b b idea'o' hein i o wil righ e an ipo f 10 Fig. 1, t in om n case of Carrier transmission, "a suitable dejthe'modulations chriiesponding itoithe''Varying' ti an'spalfencies' ef'thfe elemental areas of -m 'oplulat or 1O may lbe'pi'ovided for detecti ngjv the f atthe receivingfstatien. lhese 0 modulations 'are then applied to the field" winding 11 of an electro-mechanical repro- 'ducer of any well-known type. :As shown screen. Thus as the currentin-"winding 11.

i picture art. Positioned betweenthelight 31 like, having a series of spaced non transpan 'ent lines formed on the surface thereof; Or if desired, this screen member may take the focussed by means of a suitable optical sysg in the drawing, the modulations cause cor-re sponding vibrations in the diaphragm or armaturer12 ,of the reproducer. Sultably I linked to the member 12 isailined screen 13 which may be made of any transparent; or. translucent material, such as celluloid or the form of a very finemesh' wire fabric which is mounted in a suitable frame to beoperated by member 12. Half-tone screens which are well known in the printing art may: also be usedfor this purpose; ,Fixedly mounted ad jacent to screen member 13 is a similar screen 14. Members 13 and 14 are so positioned with. respect to each other ,thatwhen the; minimum current is applied to winding 11, the opaque lines of one screen are in registry with the transparent linesl of the other increases, the screen 13 is: given correspondng-1y ncreased vibrations and-permits correspondmgly greater amount 7 of .hght' to be transmitted through the screens.

Positioned in? the rearof screen member 13 is a source of light 31, preferably of high and constant intensity,suchiasan arc lamp or projection lamp well known inithe motion andscreen 13 is a rotating member 32 which may be similar to thev member lat the send lngstation. The light from source 31 ;is

. tem represented schematically bylens 33in the fdrmiofa spotnpon' the member'32,. Asff member 32 rotates the screen 13 islitheref ore illuminated in ap'oint-by point fashion with,

' alight spot of highiand constant intensity},

I motors 34Tand'35at the receiving andfsendthisspot movinginfsynchronism with the analyzation of the elementary areas ,of the picture 1.- 'It will be understood thatnthe ing stations are rotated, in 'synchronism eiwith the magnitude, of vibration o f screen '13 ther by local synchronizing 'meansjor, v over' the channel L as is wellknownlin the art. I

Consequently, if an observer views the screen 1' 4jfrom"the-front, the. moving spot of light appears to vary in intensityin accordance as hereinbefore described: Y

Referring to Fig. 3'there is shown another modification-of screen thatma-y be used in place cof the screenof Fig. 1. In this modi-- fication the screen comprises a thin preferably transparent metal electrodella which is fastened at opposite edgesin a suitable frame 15 Instead of a transparent metal member such as gold heaters skin or the like, the

memberM may take the form of a thin metal plate profusely perforated to pa'ss the-reqniredamount of lightas indicated the numeral 16. Mounted in the framel5 is another electrode '17 also of very thin metal, but

preferably non-transparent. Electrode 1-7- through the respective conductors 21, due'to the electrostatic attractionsand repulsions the strips 18, 19, etc. are bowed with respect to the electrode Hand the strips are corre 'pondingly separated ;-fro1n one another.

Thus the constant and high intensity moving light ,spot from source 22 when v1ewed;from

the opposite side of thescreen, appears to thestrips 18, 19' etc. If desired, instead of using strips very thin wi'resmay be em-,1

ployed, and in orderqthat the screen may have a; uniform appearance,- it is preferable to m ake the length of the-strips or wires very.

long-as compared with their' width and to utilize the central portion of the screen. i As a modification, the electrode 17 may be the same as electrode 14 and reliance place upon the{inv erse?law for the .variationqIn the latter case it is desirable, to have both electrodes movable. H

' Referring to Fig. 4, thereis shown another.

typeof screenthat may be used in place of vary in accordance with the'movements of .thescreensofFigs.land 3. Inthis modification -ga plurality of sets .of metal strips 23, 24

rovided land arranged in two parallel rows in the manner shown. Normally. the

strips are very close together to limit the" quantity of'lighti The rear row of strips 24,

25,126, etcqare connected to a common conductor 27 ,while each ofthe front strips is connected to a corresponding contact Of-a'fl' commutator 28, the brush 29 of which is'connected'toiconductor30.,' The incomingimage currents areapplied to conductors'27 and 30 whereby the set of strips'which happen, at. the moment, tobe in circuit throughcommutator 28, f are separated in accordance with the amplitude of current: Thus asshown in the drawing, brush 29 is in circuit with strips 23 and2 l, which are shown separated, while the remaining setslare Iclosed Thus, if 32. 3

mean, and high intensity light source'is placed on one side of the screen and moved in the manner shownin Fig. 1 andthen viewed from thejotherside ofthe screen, the v respective strip of the" screen will appear illuminated in accordancewith thesepara tion of the strips. Itwill be understood that each' set of strips corresponds toa linear element of the picture or image, and the brush 28 successively contacts with the sets of strips in'synchronism with the scanning of the corresponding ;linear elements at the. sending station.- If desired, the front surface of each strip may. be olished to reflect the light was is then pastime iii front offfthel screen, but the light itself 'beingfshielded -may be'eniployed, so long as thestrip or Wires of each set are connected to operateas .a unit.

' vscope of the invention. Thus-the several types of screns maybe mounted intransparent evacuated envelopes-todecrease the 1ni pedance to vibration. Likewise the relative i movements of the 1 screens may be produced by pneumatic means lnstcad'of electric means.

What'is claimedis :1 j a "1. In an image reproducing system the 'niethod of reproducing a picture at a dis.-

"Ttance vWhich comprises projecting a; moving scanning light spot of constant intensity upon a 'a first picture reproducing screen andrnov-v in a second tively to said first screen; y

'A method of'reproducing 'visual representations according to-claim 1 in which the o relative movement of the screens is. controlled by incoming image currents. V v

3. A method of reproducing 'visualrepre- Other modifications and changes may be 1 made without departing'from-the spirit and V 'sentationinto correspondingelectric currents- 7,

by analyzing each elementaljarea or the representation, projecting a moving scanning spot of light of constant intensity upon afirst" picture reproducing screen relaf p rents, means for connectingfsaid 'source-"to--;

each ofisald-setsin sucoesslon,andmeansforj iouSly moving another screen relatively. to 3 9 Y said-firstjscreenI L 4. Ainuethod according to clai1n3 inwhich I I T said light spotis viewed through both screens.)-

' i '5.. Themethod of reproducing visual representationsat a distancel'which'comprises translating the characteristicsof'the reprefscreen and vibrating a second screenfrelative N 1 0am;

pro ectinga moving scanning spot of light} on said screen. V 

